Proving the Fundamental Theorem of Calculus Twice

[steelers2147]

Homework Statement

Complete the proof by using the Fundamental Theorem of Calculus TWICE to establish
$$\int_c^d(\int_a^b f _{x}(x,y)dx)dy=...=\int_a^b(\int_{c}^{d}f_{x}(x,y) dy)dx$$

Homework Equations

I know that the FTC states that if g(x)=\int_a^x(f), then g'=f

The Attempt at a Solution

I'm not sure how to use this fact to get the proof started. Any guidance would be appreciated.

 

[Mark44]

Fixed your integral. You had [ \tex] rather than [ /tex].

Homework Statement

Complete the proof by using the Fundamental Theorem of Calculus TWICE to establish

$$\int_c^d(\int_a^b f _{x}(x,y)dx)dy=...=\int_a^b(\int_{c}^{d}f_{x}(x,y)dy)dx$$

Homework Equations

I know that the FTC states that if g(x)=\int_a^x(f), then g'=f

The Attempt at a Solution

I'm not sure how to use this fact to get the proof started. Any guidance would be appreciated.